Have you got any documentation on this subject or maybe can you explain in short terms what the differences are?

Thanks.

2nd Edit: I've tried all options and the output of this I've included below. The result is that using the MichaelAshsRegexEnhancements is the best option to use, even with different settings such as: Obfuscating or Preserving
Semicolons.

Heya DForce.
great to hear that you've found this project AND you're giving it a go :) Personally, I don't use Michael Ash's version. I just stick to YUI stock compression .. mainly because that's tried and tested.

Now, to explain the difference decompression types :-

YuiStockCompression : This is an exact port of the original JAVA source code. The only difference (so far) is that the java code uses a hashtable for obfuscation .. which means I can't get the exact same obfuscated characters as they
do. If they decide the swap an word (eg. foo) for 'A' ... my .NET code might make that a 'D' .. but it still works identical and is the same size. Just not _exactly_ character for character identical *sigh*. I have filed a bug report and patch update on the
official YUI-Compressor site ... but doubt they will get around to fixing it.

MichaelAshsRegexEnhancements : Can't remember exactly how this came about, but I think i stumbled on his code and thought I should add it in for shits and giggles. I also think it's only CSS.

HaveMyCakeAndEatIt or BestOfBothWorlds or
Hybrid : any of these three options will do BOTH behind the scenes and pick the smallest result. I was just trying to be silly with the names ... but all three do the same => try YuiStock and MichaelAsh .. and return the smallest size of ehither
of these two.

Default is YuiStockCompression. : if u do not provided an option, then i assume u just want YUI Stock.
does this help?

yes it clarifies things alot :) ( was already thinking that they where the same, as you used different namings for "Yes" :P )

I was just fiddling around with some of the options, but as you where stating that the best option is to use the YUI-Stock.

Just for the records: I'm developing a website with several javascripts in it and the loading time just decreased tremendously, from several seconds to 140ms!!! This is mainly because every js file is included in one file now, and even some compression added!

Thanks for your good work! I'll be looking forward to the next update!